Upmarket make-overs and price advice from antique dealers are pushing up prices in some charity shops.

Even the most dedicated fans of secondhand balk at prices that are far from the $2 bargains of yesteryear.

Linda Depledge-Brooker has op-shopped since her teens and blogs about her experiences as Op Shop Mama. The Hamilton mum-of five has noticed prices creeping up and has crossed the more expensive charity shops off her must-visit list.

"I have my favourites that still occasionally have the $2 bargains and I hope they stay that way," said Depledge-Brooker, whose best buys are a valuable Crown Lynn vase and a large mirror for $2 each. But such finds now are rare.

Keen op-shoppers Ann-Marie Bissett and her daughter, Laura Kvigstad, have been looking for a bedroom vanity for months, but said everything was overpriced.

"You used to be able to get cheap used furniture but now everything has a price tag of $250 or more," Kvigstad said.

Shopper Chris Bernard said the internet and antique dealers over-valuing items were partly to blame.

"Some things are sold online but staff are also able to look up items and then put higher prices on them."

Bernard believed dealers advised shops on prices but also took valuable items away and sold them for profit.

Thrift store Salvation Army is reviewing prices to ensure it is lower than sale items at chain stores such as Kmart and The Warehouse.

"We would hate for our customers to buy a shirt for $10 and then pick it up at Kmart for the same price, or lower," said spokesman Fraser Kearse. "We are all about raising money but we also want to provide cheaper goods for people who might not be able to buy new."

Kearse confirmed some items were sold through online sites or antique auctions. "It varies from shop to shop but there are some that do get advice if they spot an item that is worth a lot of money."

Mercy Hospice Auckland shops also held back valuable items and obtained pricing advice from antique dealers. Recently the Ellerslie store was given a set of three rugby caps dating back as far as 1911, plus a rugby team photo featuring the man they belonged to, William George Bell.

The woman who donated them wanted the money raised to go to Hospice. The caps fetched $2500 at an online auction.

Relative newcomer the SPCA had made good profits from three stores around Auckland. SPCA head Bob Kerridge said items were "competitively" priced but were there to make money for animal welfare.